Electronic balance

Abstract

An electronic balance including a first Roberval's chain, a second Roberval's chain connected to the first Roberval's chain, and a detector. The first Roberval's chain includes a first fixed pillar, a plurality of first beams, and a first movable pillar supported by the first fixed pillar via the plurality of first beams. The first beams extends substantially in parallel with each other and in a first extending direction. The first movable pillar is configured to receive a load to be measured. The second Roberval's chain includes a second fixed pillar, a plurality of second beams, and a second movable pillar supported by the second fixed pillar via the plurality of second beams. The plurality of second beams extends substantially in parallel with each other and in a second extending direction substantially perpendicular to the first extending direction of the plurality of first beams. The second movable pillar is connected to the first movable pillar. The detector is configured to detect the load electrically via a movement of the first movable pillar.

What is claimed as new and is desired to be secured by Letters Patent of the United States is:  
     
       1. An electronic balance comprising: 
       a first Roberval's chain comprising:  
       (1) a first fixed pillar;  
       (2) a plurality of first beams extending substantially in parallel with each other and in a first extending direction; and  
       (3) a first movable pillar supported by said first fixed pillar via said plurality of first beams and configured to receive a load to be measured;  
       a second Roberval's chain connected to the first Roberval's chain and comprising:  
       (1) a second fixed pillar;  
       (2) a plurality of second beams extending substantially in parallel with each other and in a second extending direction substantially perpendicular to the first extending direction of said plurality of first beams; and  
       (3) a second movable pillar supported by said second fixed pillar via said plurality of second beams, said second movable pillar being connected to said first movable pillar; and  
       a detector configured to detect the load electrically via a movement of said first movable pillar.  
     
     
       2. An electronic balance according to claim  1 , wherein said plurality of first beams comprises first upper and lower beams. 
     
     
       3. An electronic balance according to claim  1 , wherein said plurality of second beams comprises second upper and lower beams. 
     
     
       4. An electronic balance according to claim  1 , wherein said first Roberval's chain is formed from a single plate. 
     
     
       5. An electronic balance according to claim  1 , wherein said second Roberval's chain is formed from a single plate. 
     
     
       6. An electronic balance according to claim  1 , wherein said second movable pillar is connected to said first movable pillar via at least one screw. 
     
     
       7. An electronic balance according to claim  1 , wherein each of said plurality of second beams has at least one thin portion which has a narrow width in the first extending direction of said plurality of first beams. 
     
     
       8. An electronic balance according to claim  1 , wherein said Roberval's chain is assembled from separate pieces of the first movable pillar, the plurality of first beams, and the first movable pillar. 
     
     
       9. An electronic balance according to claim  8 , wherein each of the plurality of first beams has a V-shape. 
     
     
       10. An electronic balance according to claim  9 , wherein each of the plurality of first beams comprises, 
       two end portions of the V-shape connected to said first fixed pillar; and  
       a top end portion of the V-shape connected to said first movable pillar.  
     
     
       11. An electronic balance according to claim  1 , wherein said second Roberval's chain is assembled from separate pieces of the second fixed pillar, the plurality of second beams, and the second movable pillar. 
     
     
       12. An electronic balance according to claim  11 , wherein the second fixed pillar is connected to the first movable pillar via the plurality of second beams. 
     
     
       13. An electronic balance according to claim  1 , wherein the first movable pillar of the first Roberval's chain also operates as a second movable pillar of the second Roberval's chain. 
     
     
       14. An electronic balance according to claim  1 , wherein said detector comprises a load sensor. 
     
     
       15. An electronic balance according to claim  1 , wherein said detector comprises an electromagnetic restoring system. 
     
     
       16. An electronic balance according to claim  1 , wherein said first movable pillar further comprises: 
       a lever which is engaged with the detector and via which the detector detects the load.  
     
     
       17. An electronic balance according to claim  1 , wherein said first movable pillar further comprises: 
       a first lever connected to the first movable pillar; and  
       a second lever connected to the first lever and engaged with the detector, the detector detecting the load via the first and second levers.  
     
     
       18. A scale comprising: 
       a housing having a circumferential portion, and first and second side portions at both ends of the circumferential portion; and  
       an electronic balance provided in the housing and comprising:  
       a first Roberval's chain comprising:  
       (1) a first fixed pillar fixed to the housing;  
       (2) a plurality of first beams extending substantially in parallel with each other and in a first extending direction; and  
       (3) a first movable pillar supported by said first fixed pillar via said plurality of first beams and configured to receive a load to be measured;  
       a second Roberval's chain connected to the first Roberval's chain and comprising:  
       (1) a second pillar fixed to the housing;  
       (2) a plurality of second beams extending substantially in parallel with each other and in a second extending direction substantially perpendicular to the first extending direction of said plurality of first beams; and  
       (3) a second movable pillar supported by said second fixed pillar via said plurality of second beams, said second movable pillar being connected to said first movable pillar; and  
       a detector configured to detect the load electrically via a movement of said first movable pillar.  
     
     
       19. A scale according to claim  18 , wherein the first fixed pillar of the first Roberval's chain is fixed to the first side portion of the housing, and the second fixed pillar of the second Roberval's chain is fixed to the second side portion of the housing. 
     
     
       20. A scale according to claim  18 , wherein the first fixed pillar is fixed to an inner wall of the circumferential portion of the housing. 
     
     
       21. A scale according to claim  18 , wherein the circumferential portion of the housing has a square shape. 
     
     
       22. An electronic balance comprising: 
       a first Roberval's chain comprising:  
       (1) a first fixed pillar;  
       (2) a plurality of first beams extending substantially in parallel with each other and in a first extending direction; and  
       (3) a first movable pillar supported by said first fixed pillar via said plurality of first beams and configured to receive in a loading direction a load to be measured;  
       a second Roberval's chain connected to the first Roberval's chain and comprising:  
       (1) a second fixed pillar;  
       (2) a plurality of second beams extending substantially in parallel with each other and in a second extending direction substantially perpendicular to the first extending direction of said plurality of first beams; and  
       (3) a second movable pillar supported by said second fixed pillar via said plurality of second beams, said second movable pillar being connected to said first movable pillar; and  
       a detector configured to detect the load electrically via a movement of said first movable pillar, wherein  
       the loading direction is substantially perpendicular to the first and second extending directions.  
     
     
       23. A scale comprising: 
       a housing having a circumferential portion, and first and second side portions at both ends of the circumferential portion; and  
       an electronic balance provided in the housing and comprising:  
       a first Roberval's chain comprising:  
       (1) a first fixed pillar fixed to the housing;  
       (2) a plurality of first beams extending substantially in parallel with each other and in a first extending direction; and  
       (3) a first movable pillar supported by said first fixed pillar via said plurality of first beams and configured to receive in a loading direction a load to be measured;  
       a second Roberval's chain connected to the first Roberval's chain and comprising:  
       (1) a second fixed pillar fixed to the housing;  
       (2) a plurality of second beams extending substantially in parallel with each other and in a second extending direction substantially perpendicular to the first extending direction of said plurality of first beams; and  
       (3) a second movable pillar supported by said second fixed pillar via said plurality of second beams, said second movable pillar being connected to said first movable pillar; and  
       a detector configured to detect the load electrically via a movement of said first movable pillar, wherein the loading direction is substantially perpendicular to the first and second extending directions.